The Center for Clinical Epidemiology and Biostatistics (CCEB), the Infectious Diseases Division within the Department of Medicine, and the Division of Infectious Diseases within the Department of Pediatrics, all of the University of Pennsylvania (Penn) School of Medicine, resubmit this request for the renewal of an innovative and successful research training program for post-doctoral training for clinicians in infectious diseases clinical research. Penn and the School of Medicine promote an academic environment in which basic and clinical research are encouraged and viewed as attractive career paths for trainees. This training program attracts infectious disease trainees from other institutions nationwide and the graduates of this training program are placed in other institutions nationwide, resulting in a program of the highest impact. The two- to three-year training program consists of required courses in clinical epidemiology, research methodology, biostatistics, and infectious diseases epidemiology;elective courses;journal clubs and clinical research conferences focusing on research issues in infectious diseases;extensive independent readings;attendance at and participation in research seminars at the CCEB and the adult and pediatric infectious diseases divisions;and the completion of an independent research project. The program is designed to: 1) train clinicians to be rigorous and independent academic investigators able to use the range of approaches available in epidemiology to address research issues regarding the etiology, prognosis, prevention and early detection, treatment, clinical economics, technology assessment, medical decision making, and quality of patient care in infectious diseases;2) provide closely mentored research experiences with faculty preceptors in clinical epidemiology and infectious diseases;and 3) strengthen the links between traditional epidemiology and infectious diseases. Trainees matriculate in the Master of Science in Clinical Epidemiology (MSCE) degree program. Strengths of the proposed program are: 1) the long history of successful research training programs in the CCEB and the adult and pediatric infectious diseases divisions;2) the collaborative links that have been forged among these academic entities;3) the comprehensive course offerings and research programs that are available to trainees;and 4) an extensive set of experienced program directors and faculty preceptors with successful training records. In addition, the availability of the broad range of rich expertise of the faculties in the CCEB and the adult and pediatric infectious diseases divisions;numerous existing large databases that can be used for research projects and training;a broad array of specialized analytic capabilities available for clinical studies (e.g., clinical trials, case-control, cohort research, etc.);and the faculties'commitment to collaborative research and training, combine to provide an ideal environment for this training program.